Solo Development

What You Will Learn How Claude Code Agent Teams work and when to use them Concrete use cases for solo developers using Agent Teams Real examples of task lists and team configurations Differences between regular subagents and Agent Teams, and how to choose The Wall of Solo Development In Part 6, I wrote about developing a 220,000-line SaaS application alone using Claude Code. AI functions as “ten extra pairs of hands,” rapidly handling everything from specification drafting to implementation and testing. ...

What You Will Learn Problem and solution patterns in self-hosted runner environments How to prevent resource contention on a shared Docker daemon The port assignment problem killed by the birthday paradox How to investigate when “CI that was working suddenly breaks” Introduction In Part 2, I wrote about automating E2E tests using WebAuthn and Mailpit. The tests themselves work fine. The problem was the CI infrastructure. Saru has 4 frontends x 4 backend APIs. E2E tests run independently for each portal, plus there are cross-portal tests (integration tests between portals). Running these in parallel means 7+ jobs executing simultaneously. ...

What You’ll Learn The reality of large-scale development with Claude Code What to delegate to AI vs. what requires human judgment Actual workflow with a 200K-line codebase The Project in Numbers Metric Value Lines of code ~200K (Go 84K + TypeScript 113K) Development period ~3 months (Oct 2025–) Commits 311 Developers 1 Portals 4 (System / Provider / Reseller / Consumer) APIs 4 (dedicated to each portal) One person. Three months. 200K lines. ...

What You’ll Learn Next.js + Go monorepo architecture patterns Practical use of pnpm workspace + Turborepo Sharing UI components across 4 portals Package splitting strategies that don’t break down in solo development Introduction As introduced in Part 1, Saru is a multi-tenant SaaS with a 4-tier account structure. To implement this, I adopted an architecture of 4 frontends + 4 backend APIs. Normally, this would mean managing 8 repositories. For solo development, that would be unsustainable. ...

What You’ll Learn How to test WebAuthn (passkey) authentication in CI environments Automating OTP email retrieval with Mailpit API Preventing email race conditions in parallel E2E tests Locale-specific testing for multilingual UIs Introduction In Part 1, I introduced the overall architecture and automation strategy for “Saru,” a multi-tenant SaaS platform. This article dives deeper into the E2E testing implementation that forms the core of that automation. The most challenging aspect is testing authentication flows. Saru uses two authentication methods: ...

What You’ll Learn How to approach building systems that exceed “what one person can maintain” Overview of complex multi-tenant system design Automation strategy to achieve zero manual testing Introduction “Don’t build what you can’t maintain alone.” I believe this is a fundamental rule of solo development. But I wanted to challenge that limit. After using AI coding agents (Claude Code, GitHub Copilot, etc.) in production for several months, I started thinking, “Maybe I can build something complex on my own.” But there’s a condition: thorough automation. ...